Python书籍示例代码(第五章)

《Python语言程序设计基础（第2版）》嵩天著

第五章

●5 - 1
生日歌


def happy():
    print("Happy birthday to you!")


def happyB(name):
    happy()
    happy()
    print("Happy birthday, dear {}!".format(name))
    happy()


happyB("Mike")
print()
happyB("Lily")
●5 - 2
基本的七段数码管绘制

# e7.1DrawSevenSegDisplay.py
import turtle, datetime


def drawLine(draw):  # 绘制单段数码管
    turtle.pendown() if draw else turtle.penup()
    turtle.fd(40)
    turtle.right(90)


def drawDigit(digit):  # 根据数字绘制七段数码管
    drawLine(True) if digit in [2, 3, 4, 5, 6, 8, 9] else drawLine(False)
    drawLine(True) if digit in [0, 1, 3, 4, 5, 6, 7, 8, 9] else drawLine(False)
    drawLine(True) if digit in [0, 2, 3, 5, 6, 8, 9] else drawLine(False)
    drawLine(True) if digit in [0, 2, 6, 8] else drawLine(False)
    turtle.left(90)
    drawLine(True) if digit in [0, 4, 5, 6, 8, 9] else drawLine(False)
    drawLine(True) if digit in [0, 2, 3, 5, 6, 7, 8, 9] else drawLine(False)
    drawLine(True) if digit in [0, 1, 2, 3, 4, 7, 8, 9] else drawLine(False)
    turtle.left(180)
    turtle.penup()
    turtle.fd(20)


def drawDate(date):  # 获得要输出的数字
    for i in date:
        drawDigit(eval(i))  # 注意: 通过eval()函数将数字变为整数


def main():
    turtle.setup(800, 350, 200, 200)
    turtle.penup()
    turtle.fd(-300)
    turtle.pensize(5)
    drawDate(datetime.datetime.now().strftime('%Y%m%d'))
    turtle.hideturtle()


main()

●5 - 3
风格的七段数码管绘制

# e7.2DrawSevenSegDisplay.py
import turtle, datetime


def drawGap():  # 绘制数码管间隔
    turtle.penup()
    turtle.fd(5)


def drawLine(draw):  # 绘制单段数码管
    drawGap()
    turtle.pendown() if draw else turtle.penup()
    turtle.fd(40)
    drawGap()
    turtle.right(90)


def drawDigit(d):  # 根据数字绘制七段数码管
    drawLine(True) if d in [2, 3, 4, 5, 6, 8, 9] else drawLine(False)
    drawLine(True) if d in [0, 1, 3, 4, 5, 6, 7, 8, 9] else drawLine(False)
    drawLine(True) if d in [0, 2, 3, 5, 6, 8, 9] else drawLine(False)
    drawLine(True) if d in [0, 2, 6, 8] else drawLine(False)
    turtle.left(90)
    drawLine(True) if d in [0, 4, 5, 6, 8, 9] else drawLine(False)
    drawLine(True) if d in [0, 2, 3, 5, 6, 7, 8, 9] else drawLine(False)
    drawLine(True) if d in [0, 1, 2, 3, 4, 7, 8, 9] else drawLine(False)
    turtle.left(180)
    turtle.penup()
    turtle.fd(20)


def drawDate(date):
    turtle.pencolor("red")
    for i in date:
        if i == '-':
            turtle.write('年', font=("Arial", 18, "normal"))
            turtle.pencolor("green")
            turtle.fd(40)
        elif i == '=':
            turtle.write('月', font=("Arial", 18, "normal"))
            turtle.pencolor("blue")
            turtle.fd(40)
        elif i == '+':
            turtle.write('日', font=("Arial", 18, "normal"))
        else:
            drawDigit(eval(i))


def main():
    turtle.setup(800, 350, 200, 200)
    turtle.penup()
    turtle.fd(-350)
    turtle.pensize(5)
    drawDate(datetime.datetime.now().strftime('%Y-%m=%d+'))
    turtle.hideturtle()


main()
●5 - 4
阶乘的计算


def factorial(num):
    if num == 0:
        return 1
    else:
        return num * factorial(num - 1)


n = eval(input("请输入一个整数: "))
print(factorial(abs(int(n))))
5 - 5
字符串反转


def reverse(s):
    if s == "":
        return s
    else:
        return reverse(s[1:]) + s[0]


str = input("请输入一个字符串: ")
print(reverse(str))
●5 - 6
科赫曲线的绘制

# e8.1DrawKoch.py
import turtle


def koch(size, n):
    if n == 0:
        turtle.fd(size)
    else:
        for angle in [0, 60, -120, 60]:
            turtle.left(angle)
            koch(size / 3, n - 1)


def main():
    turtle.setup(800, 400)
    turtle.speed(0)  # 控制绘制速度
    turtle.penup()
    turtle.goto(-300, -50)
    turtle.pendown()
    turtle.pensize(2)
    koch(600, 6)  # 0阶科赫曲线长度，阶数
    turtle.hideturtle()


main()
●5 - 7
科赫曲线的雪花效果

# e8.2DrawKoch.py
import turtle


def koch(size, n):
    if n == 0:
        turtle.fd(size)
    else:
        for angle in [0, 60, -120, 60]:
            turtle.left(angle)
            koch(size / 3, n - 1)


def main():
    turtle.setup(600, 600)
    turtle.speed(0)
    turtle.penup()
    turtle.goto(-200, 100)
    turtle.pendown()
    turtle.pensize(2)
    level = 5
    koch(400, level)
    turtle.right(120)
    koch(400, level)
    turtle.right(120)
    koch(400, level)
    turtle.hideturtle()


main()